CVE-2019-19338

Name	CVE-2019-19338
Description	A flaw was found in the fix for CVE-2019-11135, in the Linux upstream kernel versions before 5.5 where, the way Intel CPUs handle speculative execution of instructions when a TSX Asynchronous Abort (TAA) error occurs. When a guest is running on a host CPU affected by the TAA flaw (TAA_NO=0), but is not affected by the MDS issue (MDS_NO=1), the guest was to clear the affected buffers by using a VERW instruction mechanism. But when the MDS_NO=1 bit was exported to the guests, the guests did not use the VERW mechanism to clear the affected buffers. This issue affects guests running on Cascade Lake CPUs and requires that host has 'TSX' enabled. Confidentiality of data is the highest threat associated with this vulnerability.
Source	CVE (at NVD; CERT, LWN, oss-sec, fulldisc, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, GitHub advisories/code/issues, web search, more)

Vulnerable and fixed packages

The table below lists information on source packages.

Source Package	Release	Version	Status
linux (PTS)	buster	4.19.249-2	fixed
	buster (security)	4.19.304-1	fixed
	bullseye	5.10.209-2	fixed
	bullseye (security)	5.10.205-2	fixed
	bookworm	6.1.76-1	fixed
	bookworm (security)	6.1.85-1	fixed
	trixie	6.6.15-2	fixed
	sid	6.7.12-1	fixed

The information below is based on the following data on fixed versions.

Package	Type	Release	Fixed Version	Urgency	Origin	Debian Bugs
linux	source	(unstable)	(not affected)

Notes

- linux <not-affected> (Only affects specific distro kernels which do not include commit e1d38b63acd8)
https://www.openwall.com/lists/oss-security/2019/12/10/3
https://www.openwall.com/lists/oss-security/2019/12/11/1